Method of construction and footware using mated components

ABSTRACT

A method and apparatus for forming footwear, such as a sandal, with a footstrap secured to a sole by way of engagement of an insertion portion with a recess. The recess may be molded into a portion of the sole with an exposed opening at the outer surface of the sole leading to the recess formed in the sole interior. The exposed opening may be smaller in area than an area of the recess within the sole, and may be smaller that a largest cross-sectional area of the insertion portion. Thus, the insertion portion may be forced through the exposed opening, e.g., by deforming the insertion portion and/or the sole portion at the exposed opening, and received within the recess. The sole and/or insertion portion may be formed of a molded foam, e.g., that is resilient and water resistant.

The application claims the benefit of U.S. Provisional application 60/833,888, filed Jul. 28, 2006 and is hereby incorporated by reference in its entirety.

BACKGROUND

Footwear, such as sandals, commonly include one or more footstraps attached to a sole that function to secure a wearer's foot to the sole during normal use, e.g., walking, climbing stairs, running, etc. One type of sandal, commonly called a “flip flop”, has a footstrap attached to the sole by passing distal ends of the footstrap through holes formed in the sole. The extreme distal ends of the footstrap are formed to have a stopper member, e.g., in the shape of a disc, that is located at the bottom of the sole and prevents the footstrap portion from being pulled through the hole in the sole.

SUMMARY OF INVENTION

In one aspect of the invention, a footwear strap may be attached to a sole by way of a “blind hole”, e.g., a recess formed in the sole that extends from the outer surface of the sole into an internal volume, but does not require a hole be formed through the sole. In one embodiment, the blind hole may be arranged so that the cross-sectional area of the recess increases with depth into the sole, e.g., so that an opening at the outer surface of the sole that leads to the recess has an area that is less than an area of the recess at a location deeper within the sole. Such an arrangement may allow a bulbous or other relatively enlarged distal end portion of a footstrap to be inserted into the recess to secure the footstrap to the sole, e.g., by a friction fit or adhesive that permanently bonds the footstrap distal end in the recess. This aspect of the invention may provide for a more attractive attachment of the footstrap (e.g., by eliminating the visible strap end at the bottom or treadside of the sole) and/or reduce assembly costs because of the relative ease with which the footstrap may be secured in the recess.

In another aspect of the invention, a piece of footwear, such as a sandal, may have two components that are mated together for use as a structural part of the footwear. In one embodiment, one of the components may have a recess that receives an insertion portion of the second component. The recess and insertion portion may be constructed and arranged so that the first and second components can be permanently secured together, e.g., to withstand the normal stresses of use of the footwear. For example, the first component may be a sole portion of the footwear, and the second component may be a footstrap that helps to hold a wearer's foot to the sole. One or both of the components may be made of a molded foam, e.g., an injection molded foam that is light and provides cushioning for the foot, yet is durable and resistant to damage by water. The sole portion may have a recess that has a relatively small exposed opening, but has a larger opening cross section deeper within the recess. The strap may have a bulbous member that functions as the insertion portion and that is larger than the exposed opening of the recess. The first component may be resilient in the area near the exposed opening, and/or the insertion portion of the strap may have a resilient portion to allow the insertion portion to be inserted through the recess opening. Once passed into the opening, the insertion portion may be arranged to closely conform to the recess to help hold the insertion portion in place relative to the recess. The insertion portion may be secured in the recess by adhesive or other mechanical fastener, such as a pin, screw or other.

This aspect of the invention may allow for easier manufacturing of footwear and/or may provide a more durable and attractive arrangement when securing footwear portions together. For example, this aspect of the invention may allow for unitary molding of a sole and one or more footstraps without requiring complicated (and expensive) molding tools. In other embodiments, different materials may be used for the two footwear components, providing for enhanced footwear design options. For example, a sole portion may be made of an injection molded foam material, and a footstrap portion may be made of a polymer webbing, leather or other material. The footstrap may be secured to the sole, at least in part, using one or more aspects of the invention to provide attractive and functional footwear.

In another aspect of the invention, a method for forming footwear includes providing a footstrap, having an insertion portion, that is constructed and arranged to extend over at least a portion of a wearer's foot and secure the wearer's foot to the footwear. A sole of the footwear is also provided and has a recess molded into a portion of the sole with an opening at an outer surface of the sole leading to the recess. A top portion of the sole has a footbed arranged to contact a wearer's foot and a bottom portion of the sole is arranged to contact a surface on which the wearer stands when wearing the footwear. The portion of the sole in which the recess is formed is constructed and arranged to receive the insertion portion and secure the footstrap to the sole, and the recess is formed in the sole without requiring a throughhole being formed in the sole, e.g., a hole being formed from a top of the sole to the bottom, or from one side to the other. The insertion portion is secured in the recess to attach the footstrap to the sole by passing the insertion portion through the opening and into the recess. With the insertion portion attached in the recess, engagement of the footstrap with the sole may be maintained during intended wearing of the footwear by a wearer.

In another aspect of the invention, footwear, such as a sandal, includes a sole constructed and arranged to support a wearer's foot, with the sole including a top portion having a footbed arranged to contact a wearer's foot and a bottom portion arranged to contact a surface on which the wearer stands when wearing the footwear The sole may include a recess molded into a portion of the sole and formed without requiring a throughhole being formed in the sole. A footstrap may be constructed and arranged to secure a wearer's foot to the sole and include an insertion portion secured to the sole within the recess and arranged to securely attach the footstrap to the sole.

In one embodiment, the opening in the sole leading into the recess may be smaller in area than a largest cross-sectional area of the insertion portion, e.g., the insertion portion and/or the portion of the sole at the opening may be resilient to allow the insertion portion to be passed through the opening and into the recess. In some embodiments, the insertion portion and the recess may be formed so that the entire insertion portion is received in the recess and is positioned within an outer surface of the sole.

The footstrap may or may not be integrally molded with the sole (or a portion of the sole), and the footstrap and/or the sole may be molded of a foam material.

These and other aspects of the invention will be appreciated from the following description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the invention are described with reference to illustrative embodiments in which like reference numerals refer to like elements, and in which:

FIG. 1 shows an embodiment of footwear having a footstrap with insertion portions located at the distal end of three strap portions;

FIG. 2 shows an insertion portion being inserted into a recess;

FIG. 3 shows another embodiment with an insertion portion located on a toebar of a footstrap;

FIG. 4 shows another embodiment with a pair of footstraps that are integrally molded with a sole; and

FIG. 5 shows another embodiment with a footstrap having four insertion portions.

DETAILED DESCRIPTION

Aspects of the invention are described herein with reference to illustrative embodiments, but it should be understood that aspects of the invention are not limited to the embodiments described. For example, embodiments described herein have an insertion portion located on a distal end of a strap portion that is inserted into a recess in a sole. However, aspects of the invention may involve the use of an insertion portion on the sole that is engaged with a recess on a strap portion. Also, aspects of the invention may be employed alone, or in any suitable combination with one or more other aspects of the invention.

FIG. 1 shows a first embodiment of a piece of footwear that incorporates aspects of the invention. In this illustrative embodiment, the footwear 1 includes a sole 2 that is formed as a single injection molded foam piece, but the sole 2 could be formed in any suitable way, such as by two or more laminated or otherwise joined pieces (e.g., a footbed portion that is bonded to an outsole portion). The sole 2 may have any suitable features, such as an outsole that has traction enhancing features, a footbed portion that is conformable to a wearer's foot or otherwise makes the footwear more comfortable and/or stable, resistance to damage by water, openings that provide for ventilation and/or water draining, or other. Moreover, the sole 2 may have multiple components, if desired, such as a footbed portion that is removable from an outsole portion.

In this embodiment, the footwear 1 is arranged much like a common “flip flop” and includes a footstrap 3 with medial and lateral rear strap portions 3 a and 3 b and a toebar portion 3 c. Each of the portions 3 a-3 c include an insertion portion that is mated with a corresponding recess 21 in the sole 2. The insertion portions may be arranged in any suitable way, and in this embodiment, the insertion portion for the toebar 3 c is formed as a disc-shaped member, while the insertion portions for the rear strap portions 3 a and 3 b have a cylinder-like shape with rounded ends. Of course, it will be understood by those of skill in the art that the insertion portions may be arranged in other ways, such as in a box-like shape, a bayonet arrangement, a tab, a spherical shape, etc. The recesses 21 in the sole 2 are formed so that an exposed opening of the recess (i.e., the entrance to the recess at the outer surface of the sole) is smaller in size (area) than a largest cross sectional area of the insertion portion. However, the recesses 21 open into a larger cavity in the sole 2 that receives the insertion portion of the strap, and the portion of the sole at the exposed opening and/or the insertion portion may be resilient to allow the insertion portion to pass through the opening and into the recess 21. Thus, once the insertion portion is properly seated in the recess, the insertion portion may tend to stay in place, even during normal use by the wearer. The insertion portion may be better secured in the recess 21 by an adhesive, pin or other fastening arrangement. The recess 21 may include other locking features for the insertion portion, e.g., the recess may include a tab, lug, boss or other feature that engages with an opening formed in the insertion portion to help secure the insertion portion in the recess 21.

FIG. 2 shows a cross sectional view of the recess 21 for the toebar 3 c along the line 2-2 in FIG. 1. As can be seen in FIG. 2, the recess 21 opens into a larger cavity within the sole 2 that receives the disc-shaped insertion portion on the toebar 3 c. Although the exposed opening of the recess 21 may be smaller than the largest diameter of the insertion portion for the toebar 3 c, compliance of the insertion portion and/or the portion of the sole near the recess 21 may allow the insertion portion to be inserted into the recess 21. For example, the sole 2 may be made of an injected foam material that is resilient, while the toebar 3 c and insertion portion may be made of a more rigid plastic or other material. As the insertion portion is inserted, e.g., shown in FIG. 2, the exposed opening of the recess 21 may expand to allow the insertion portion to pass, and then close back to closely approximate the size of the toebar 3 c above the insertion portion. As described above, an adhesive may be placed in the recess 21 before assembly and cured to fix the insertion portion in the recess. Any suitable adhesive may be used, including urethane adhesives, epoxies, UV or other light curable adhesives, and others. For UV or other light curable adhesives, illumination may be provided into the recess by optical fiber or other suitable means.

FIG. 3 shows another embodiment in which a sandal 1 includes a sole 2 that is formed as a single unitary piece with a footstrap 3. In this embodiment, the rear strap portions 3 a and 3 b are molded integrally with the sole, and therefore require no assembly with the sole 2. However, the toebar portion 3 c, although molded integrally with other portions of the footstrap 3, is not attached to the sole 2 during molding. Instead, the toebar portion 3 c is attached to the sole 2 in the same way as in the FIG. 1 embodiment. This arrangement may allow for easier and less expensive molding tools since the mold need not accommodate a connection between the toebar and sole.

FIG. 4 shows another illustrative embodiment in which a pair of footstraps 3 are molded integrally with the sole 2 so as to be attached on one side, e.g., the medial side, but are free from the sole 2 at the opposite end. The free end of the straps 3 may include an insertion portion that is received into a corresponding recess 21, e.g., at the lateral side of the sole 2. Such an arrangement may allow for easier molding of the footwear 2. Although the footstraps are shown in a relatively simple arrangement, those of skill in the art will appreciate that the footstraps may take any suitable form, shape or other configuration. For example, the footstraps 3 in the FIG. 4 embodiment may have one or more members that connect the footstraps 3 together and extend over the wearer's instep when the footwear is worn. In another illustrative embodiment, the footstrap(s) 3 may form a clog-type covering over the wearer's foot and be attached to the sole 2 by way of insertion portions located around the sole perimeter. Although not shown, the footstrap may include a heel strap portion that may be attached to another footstrap portion, or may be separate from other footstrap portions.

FIG. 5 shows another illustrative embodiment of a piece of footwear 1 having a footstrap 3 that is initially formed separately from the sole 2. The strap 3 may be attached to the sole 2 at several points around the periphery of the footbed and arranged to secure the foot to the sole. The unique arrangement of the strap 3 in the FIG. 5 embodiment is also an aspect of the invention, e.g., one inventive feature includes the way in which the strap 3 engages at a rear medial side of the sole, extends around the wearer's heel to engage at a rear lateral side of the sole, then extends over the wearer's instep to engage at a front medial side of the sole and at a front lateral side of the sole. This strap arrangement provides a sandal that is easy to place on the foot, yet stays securely on the foot during walking, etc.

Although aspects of the invention have been described with reference to illustrative embodiments, aspects of the invention are not limited to these illustrative embodiments. Instead, aspects of the invention may be used in any suitable way in any suitable type of footwear. 

1. A method for forming footwear, comprising: providing a footstrap having an insertion portion, the footstrap being constructed and arranged to extend over at least a portion of a wearer's foot and secure the wearer's foot to the footwear; providing a sole of the footwear having a recess molded into a portion of the sole and an opening at an outer surface of the sole leading to the recess, a top portion having a footbed arranged to contact a wearer's foot and a bottom portion arranged to contact a surface on which the wearer stands when wearing the footwear, the sole portion having the recess being constructed and arranged to receive the insertion portion and secure the footstrap to the sole, the recess being formed in the sole without requiring a throughhole being formed in the sole; and securing the insertion portion in the recess to attach the footstrap to the sole by passing the insertion portion through the opening and into the recess, attachment of the insertion portion in the recess being suitable to maintain engagement of the footstrap with the sole during intended wearing of the footwear by a wearer.
 2. The method of claim 1, wherein the insertion portion and the recess are formed so that the opening in the sole leading into the recess is smaller in area than a largest cross-sectional area of the insertion portion.
 3. The method of claim 1, wherein the insertion portion and the recess are formed so that the entire insertion portion is received in the recess and is positioned within an outer surface of the sole.
 4. The method of claim 1, wherein the insertion portion is permanently bonded in the recess.
 5. The method of claim 1, wherein the insertion portion is integrally molded with the footstrap.
 6. The method of claim 5, wherein the insertion portion and footstrap are molded from a foam material.
 7. The method of claim 1, wherein the footstrap is integrally molded with a portion of the sole.
 8. The method of claim 1, wherein the sole is formed as a unitary member molded from a foam material.
 9. The method of claim 1, wherein the footstrap includes a toe bar and lateral and medial rear strap portions, and one of the toe bar and lateral and medial rear strap portions includes the insertion portion at a distal end.
 10. The method of claim 9, wherein all of the toe bar and lateral and medial rear strap portions include an insertion portion at a respective distal end, and the step of securing includes securing the insertion portion for the toe bar and lateral and medial rear strap portions in a respective recess in the sole.
 11. Footwear comprising: a sole constructed and arranged to support a wearer's foot, the sole including a top portion having a footbed arranged to contact a wearer's foot and a bottom portion arranged to contact a surface on which the wearer stands when wearing the footwear, the sole including a recess molded into a portion of the sole and formed without requiring a throughhole being formed in the sole; and a footstrap constructed and arranged to secure a wearer's foot to the sole, the footstrap including an insertion portion secured to the sole within the recess and arranged to securely attach the footstrap to the sole.
 12. The footwear of claim 11, wherein the insertion portion and the recess are formed so that an opening in the sole leading into the recess is smaller in area than a largest cross-sectional area of the insertion portion.
 13. The footwear of claim 11, wherein the insertion portion and the recess are formed so that the entire insertion portion is received in the recess and is positioned within an outer surface of the sole.
 14. The footwear of claim 11, wherein the insertion portion is permanently bonded in the recess.
 15. The footwear of claim 11, wherein the insertion portion is integrally molded with the footstrap.
 16. The footwear of claim 15, wherein the insertion portion and footstrap are molded from a foam material.
 17. The footwear of claim 11, wherein the footstrap is integrally molded with a portion of the sole.
 18. The footwear of claim 17, wherein the footstrap and sole are molded from a foam material.
 19. The footwear of claim 11, wherein the footstrap includes a toe bar and lateral and medial rear strap portions, and one of the toe bar and lateral and medial rear strap portions includes the insertion portion at a distal end.
 20. The footwear of claim 19, wherein all of the toe bar and lateral and medial rear strap portions include an insertion portion at a respective distal end, and the step of securing includes securing the insertion portion for the toe bar and lateral and medial rear strap portions in a respective recess in the sole.
 21. The footwear of claim 11, wherein an opening leading into the recess is formed in a top of the sole.
 22. The footwear of claim 11, wherein the sole is integrally molded from a foam material.
 23. The footwear of claim 11, wherein the recess is formed in a central portion of a footbed portion of the sole.
 24. The footwear of claim 11, wherein the recess is formed near a lateral or medial side of the sole.
 25. The footwear of claim 11, wherein the insertion member includes a disc-like shape.
 26. The footwear of claim 11, wherein the insertion member includes a cylinder-like shape.
 27. Footwear comprising: a sole constructed and arranged to support a wearer's foot, the sole being molded of a foam material as a single unitary member and including a top portion having a footbed arranged to contact a wearer's foot and a bottom portion arranged to contact a surface on which the wearer stands when wearing the footwear, the sole including a recess molded into a portion of the sole and formed without requiring a throughhole being formed in the sole; and a footstrap constructed and arranged to secure a wearer's foot to the sole, the footstrap being molded from a foam material and including an insertion portion secured to the sole within the recess and arranged to securely attach the footstrap to the sole; wherein an opening in the sole leading into the recess is smaller in area than a largest cross-sectional area of the insertion portion and the entire insertion portion is received in the recess and is positioned within an outer surface of the sole. 